using System;
using System.Collections.Generic;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using System.Threading;


namespace App3._
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>

    public partial class Window1 : System.Windows.Window
    {
        public delegate void CounterDelegate();
        public delegate void WorkerDelegate();

        public Window1()
        {
            InitializeComponent();
        }

        public void OnClick(object sender, RoutedEventArgs args)
        {
            _isCounting = !_isCounting;

            if (_isCounting)
            {
                CounterDelegate newThread = new CounterDelegate(Counter);
                newThread.BeginInvoke(null, null);
            }
        }

        public void Counter()
        {
            while (_isCounting)
            {
                _counter++;
                
                Dispatcher.BeginInvoke(System.Windows.Threading.DispatcherPriority.SystemIdle,
                    new WorkerDelegate(Worker));

                Thread.Sleep(500);
            }
        }

        public void Worker()
        {
            button.Content = _counter;
        }

        int _counter = 0;
        bool _isCounting = false;
    }
}